Is this SPD?

My daughter is 2 and half years old. She is development delayed. We have an impossible time trying to get her to eat anything, including milk. The problem is she will hold food (pureed food, milk.. etc) in her mouth. She will let it pooled and then it either falls from her open mouth or she will gag from trying to gulp it down. Getting her to have any solid is impossible at this point. She also feels nauseous in the morning daily and it seems to be better in the afternoon. Does anyone run across this as SPD? thanks!